Video display system, video display device, and video display method

Abstract

The video display system includes a marker, a first polarizing filter, a video display device, and an amount-of-change calculation unit. The video display device includes a camera, a display unit, and a second polarizing filter. The first polarizing filter is arranged to correspond to the marker. The camera captures the marker. The second polarizing filter is arranged to correspond to the display unit, and has polarization characteristics contrary to the first polarizing filter. The amount-of-change calculation unit calculates an amount of change between a first image acquired in a first attitude and a second image acquired in a second attitude by the camera, and calculates an amount of change in attitude in accordance with the amount of change between the first image and the second image.

What is claimed is: 
     
         1 . A video display system comprising:
 a marker having a reference pattern;   a first polarizing filter arranged to correspond to the marker and having a first polarization characteristic;   a video display device including a camera configured to capture the marker via the first polarizing filter, a display unit having a light transmission property, and a second polarizing filter arranged to correspond to the display unit and having a second polarization characteristic contrary to the first polarizing filter; and   an amount-of-change calculation unit configured to calculate an amount of change between a first image obtained such that the camera captures the reference pattern in a first attitude and a second image obtained such that the camera captures the reference pattern in a second attitude, and calculate an amount of change in an attitude in accordance with the amount of change between the first image and the second image.   
     
     
         2 . The video display system according to  claim 1 , wherein the first polarizing filter and the second polarizing filter are arranged between the marker and the display unit in a state in which the marker and the display unit are opposed to each other. 
     
     
         3 . The video display system according to  claim 1 , wherein the amount-of-change calculation unit calculates the amount of change in the attitude of the video display device in accordance with a shifted amount of a second image pattern in the second image in a horizontal direction and a vertical direction corresponding to a first image pattern in the first image, and an amount of change in a length of the second image pattern in the horizontal direction and the vertical direction corresponding to the first image pattern. 
     
     
         4 . The video display system according to  claim 1 , further comprising a control device including the amount-of-change calculation unit and a first communication unit,
 wherein the video display device further includes a second communication unit connected to the first communication unit, and outputs the first image and the second image to the control device via the first communication unit and the second communication unit, and   the amount-of-change calculation unit calculates the amount of change between the first image and the second image, and calculates the amount of change in the attitude of the video display device in accordance with the amount of change between the first image and the second image.   
     
     
         5 . A video display device comprising:
 a display unit having a light transmission property;   a first polarizing filter having a first polarization characteristic arranged to correspond to a marker having a reference pattern;   a second polarizing filter arranged to correspond to the display unit and having a second polarization characteristic contrary to the first polarizing filter;   a camera configured to acquire a first image by capturing the marker via the first polarizing filter in a first attitude and a second image by capturing the marker via the first polarizing filter in a second attitude; and   an amount-of-change calculation unit configured to calculate an amount of change between the first image and the second image, and calculate an amount of change in an attitude in accordance with the amount of change between the first image and the second image.   
     
     
         6 . A video display method comprising:
 arranging a first polarizing filter having a first polarization characteristic to correspond to a marker having a reference pattern   arranging a second polarizing filter having a second polarization characteristic contrary to the first polarizing filter to correspond to a display unit;   causing a camera of a video display device to acquire a first image by capturing the marker via the first polarizing filter in a first attitude and a second image by capturing the marker via the first polarizing filter in a second attitude; and   causing an amount-of-change calculation unit to calculate an amount of change between the first image and the second image, and calculate an amount of change in an attitude in accordance with the amount of change between the first image and the second image.